Using symplectic integrator propagator, a three-dimensional fourth-order symplectic finite difference time domain （SFDTD） method is studied, which is of the fourth order in both the time and space domains. The metho...
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Using symplectic integrator propagator, a three-dimensional fourth-order symplectic finite difference time domain （SFDTD） method is studied, which is of the fourth order in both the time and space domains. The method is nondissipative and can save more memory compared with the traditional FDTD method. The total field and scattered field （TF-SF） technique is derived for the SFDTD method to provide the incident wave source conditions. The bistatic radar cross section （RCS） of a dielectric sphere is computed by using the SFDTD method for the first time. Numerical results suggest that the SFDTD algorithm acquires better stability and accuracy compared with the traditional FDTD method.
To complete the scattering analysis of an arbitrary shaped perfectly electric conductor over a wide frequency band, the Chebyshev polynomial of first kind is applied. The Chebyshev nodes within a given frequency range...
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To complete the scattering analysis of an arbitrary shaped perfectly electric conductor over a wide frequency band, the Chebyshev polynomial of first kind is applied. The Chebyshev nodes within a given frequency range are found, and then the surface electric currents at these nodes are computed by the method of moments. The surface current is expanded in a polynomial function via the Chebyshev approximation. Using this function, the electric current distribution can be obtained at any frequency within the given frequency range. The numerical results are compared with the results obtained by the method of moments, and the complexity of computation is reduced obviously.
Target detection by a noncooperative illuminator is a topic of general interest in the electronic warfare *** of all,direct-path interference(DPI)suppression which is the technique of bottleneck of moving target detec...
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Target detection by a noncooperative illuminator is a topic of general interest in the electronic warfare *** of all,direct-path interference(DPI)suppression which is the technique of bottleneck of moving target detection by a noncooperative frequency modulation(FM) broadcast transmitter is analyzed in this article;Secondly,a space-time-frequency domain synthetic solution to this problem is introduced:Adaptive nulling array processing is considered in the space domain,DPI cancellation based on adaptive fractional delay interpolation(AFDI)technique is used in planned time domain,and long-time coherent integration is utilized in the frequency domain;Finally,an experimental system is planned by considering FM broadcast transmitter as a noncooperative illuminator,Simulation results by real collected data show that the proposed method has a better performance of moving target detection.
In tile process of the reconstruction of digital holography. the traditional methods of diffraction and filtration are commonly adopted to recover the original complex-wave signal. Influenced by twin-image and zero-or...
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In tile process of the reconstruction of digital holography. the traditional methods of diffraction and filtration are commonly adopted to recover the original complex-wave signal. Influenced by twin-image and zero-order terms, the above-mentioned methods, however, either limit tile field of vision or result in the loss of the amplitude and phase. A new method for complex-wave retrieval is presented, which is based on blind signal separation. Three frames of holograms are captured by a charge coupled device （CCD） camera to form an observation signal. The term containing only amplitude and phase of complex-wave is separated, by means of independent component analysis, from the observation signal, which effectively eliminates the zero-order term. Finally. the complex-wave retrieval of pure phase wavefront is achieved. Experimental results show that this method can better recover the amplitude and phase of the original complex-wave even when there is a frequency spectrum mixture in the hologram.
Based on a Pade approximation, a wide-angle parabolic equation method is introduced for computing the multiobject radar cross section （RCS） for the first time. The method is a paraxial version of the scalar wave equ...
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Based on a Pade approximation, a wide-angle parabolic equation method is introduced for computing the multiobject radar cross section （RCS） for the first time. The method is a paraxial version of the scalar wave equation, which solves the field by marching them along the paraxial direction. Numerical results show that a single wide-angle parabofic equation run can compute multi-object RCS efficiently for angles up to 45 ° . The method provides anew and efficient numerical method for computation electromagnetics.
This paper describes a new algorithm for image semi-supervised clustering. In particular, the proposed approach introduces corner-oriented attributed graphs(COAG) constructed based on modified Harris corner extraction...
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Nowadays, the efficient representation of a given shape plays a significant role in pattern recognition field. In this paper, we introduce a novel method to represent 2-D shape as a relation graph which using affine-i...
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Modelling mixtures of multivariate t-distributions are usually used instead of Gaussian mixture models(GMM) as a robust approach, when one fits a set of continuous multivariate data which have wider tail than Gaussian...
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Barcode has been widely applied in the modern world. This paper presents a fast and robust recognition method of noisy Code 39 barcode. The proposed method can be divided into two steps: search and decoding. In the fi...
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In chaos control fields, the nonfeedback and the nonlinear feedback approaches are inevitable much less flexible. However linear feedback controllers are easy to implement, especially in electrical systems. In this pa...
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